1990 70hp evinrude randomly dies

jrbass

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Sep 16, 2010
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alright so I took off most of the gas lines in the motor running from the filter to the vro and a few from there to the carbs. all lines looked fine with no holes put it all back together getting all connections tight as possible. pumped the primer buld and the engine fire on second turn of the key. idled for about 2 minutes and just died. cant get it back started. any suggestions??? the help would be appreciated.
 

Suavecat

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Re: 1990 70hp evinrude randomly dies

Did you check your fuel fittings at the motor and the tank?
If they are all fine, next step would be to make sure fuel pump is pumping, in your case the VRO acts as the fuel pump also.
You could T in a vacume gauge in the line before it enters the VRO or before it enters the fitting at the motor pan.
There are other ways to determin if the pump is drawing in fuel, but the vacume gauge is the most conventional.

Good luck!
 

jtexas

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Oct 13, 2003
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Re: 1990 70hp evinrude randomly dies

Why do you suspect it's starved for fuel? Is the primer bulb soft after it dies? Are the carb bowls empty? It's just as likely to be flooded. How long since your last carb rebuild?

What do the spark plugs tell you?

Did you check for spark after it died?
What's the compression on this motor?

What's your idle RPM?
 

jrbass

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Re: 1990 70hp evinrude randomly dies

Plugs replaced, fule filter replaced, all gas lines and connections are good, carbs rebuilt 2 months ago. compresion is low about 70 lbs on all cylinders.

Primer bulb is soft while idling? normal?
Im confused why it will run fine one day and wont start the next. Went down and it started and idled fine today. havent had time to run it in the past couple days. Also while running it will sometimes cut out.
 

patrick4266

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Nov 29, 2007
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Re: 1990 70hp evinrude randomly dies

compression is awful low. Are you using a fully charged battery and good starter? Make sure you take all the plugs out when running the test and try a different gauge.
 

ezeke

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Sep 19, 2003
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Re: 1990 70hp evinrude randomly dies

Test your primer solenoid; it may be flooding your engine if the valve is not working correctly.
 

jtexas

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Re: 1990 70hp evinrude randomly dies

did your symptoms start immediately following the carb rebuild 2 months ago, or before the rebuild, or some time after?

replacing spark plugs isn't the same as checking for spark.

To quickly determine whether spark is being produced is to pull a plug, reattach it to the boot, hold it against the block and look for spark during cranking. (use a plastic or insulated tool)

To test the quality of the spark, get an inline spark tester (couple bucks at autozone), set the gap for 7/16", clip it to the engine block, attach the plug leads (one at a time) and look for a strong blue spark while cranking. If it can't jump a half-inch gap in the open air without a spark plug, it's not firing in the hole under heat & compression.

When it dies, or when it won't start, are the plugs wet or dry after cranking? Do they all have the same appearance or is one different from the others?

While the engine's running, the bulb is just a fat spot in the fuel line -- fuel is flowing through it so it doesn't stay hard. But if the pump is keeping the carb bowls full, it will be firm when the engine shuts down, and should stay firm all day.

patrick is right, 70 PSI is too low, although equal across all cyl is good -- did you test a cold or warm engine? spin the engine several times on each hole?
 

jrbass

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Sep 16, 2010
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Re: 1990 70hp evinrude randomly dies

Hey guys thanks for all the help. Upon inspection of the VRO pump I found the plastic housing was cracked. Got a good deal from a neighboring marina yesterday. should be here first part of next week. Ill update to let u know of any further problems.
Thanks again
 
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